Retaining Moisture in Sandy Soil

 

Many producers have converted to no-till, and now progressive farmers are learning to cover crop to keep soil covered after harvesting a cash crop. Ryan Speer is such a producer. He farms in central Kansas along the Arkansas River south of Halstead. He grows corn, soybeans, wheat and milo, in sandy soil poor at retaining moisture. Ryan started cover-cropping in 2007. By improving the biological material in his soil, more moisture is being stored from precipitation events.

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This is Playa Country — a weekly look at the wildlife, wetlands and prairies of the western Great Plains, and the people who manage them — brought to you by Playa Lakes Joint Venture, an organization dedicated to conserving birds and bird habitat.

Our topic is preventing another dust bowl, and a good place to begin that discussion is to contrast how society, and government viewed the land then — and now. From the late 1800s in the runup to the dust bowl, people were encouraged to plow and plant. The land was a resource to be mined.

“Then came the cattleman, overgrazing and scarring the lush plains grass that held the water in the soil. In 1887, the farmer came, heedlessly ripping away the protective cover of turf that kept the soil from blowing away.”

That’s a young Walter Cronkite, reporting a CBS “Twentieth Century” documentary in the early 1950s. In the 80 years since the dust bowl era, soil science and agricultural practices have come a long way. The mind-set no longer is to mine the soil, but rather to protect and enhance the resource. Soil experts say keep a canopy over the soil and disturb it as little as possible. Many producers have converted to no-till practices. More recently, progressive farmers are learning to cover crop — to sew plants, often a variety of plants, to keep the soil covered after harvesting a cash crop.

Ryan Speer is one such producer. He farms in central Kansas along the Arkansas River south of Halstead. He grows corn, soybeans, wheat and milo, in sandy soil which is lousy at moisture retention. Ryan started cover-cropping in 2007.

“We do a lot of cereal rye, radishes, oats, winter annual grasses. We’ll plant after corn in fields that will be planted to soybeans next year. We usually do almost every acre, every year, regardless of the moisture situation.”

When cover cropping, these producers typically don’t sew one type of plant. You’ll hear producers speak about a “cocktail” of plants, and the contents of that cocktail are determined based on the goal of the cover and, certainly, on the amount of rainfall the region receives — or the amount of moisture the producer can stand to give up to this non-cash crop. Remember, Ryan Speer farms sandy soil. He is all about increasing the amount of organic matter.

“Sandy soils have low water holding capacity and you’re not going to change that. But if you can increase the organic matter, you’re going to improve that somewhat.”

On this part of the High Plains, rainfall often is delivered really, really hard and really fast from thunderstorms.

“So we need the ability to capture that and keep it on the soil, instead of letting it wash down into the ditch. The residue buffers that from beating down the soil, and we get a lot better water infiltration. We’re able to capture a higher percentage of the violent rains.”

It sounds like this central Kansas producer, challenged by sandy soil, is making cover cropping work. I asked NRCS agronomist for Kansas what she sees out there, generally, negative or harmful to soil. Candy Thomas says, a lot of it’s simply habit.

“A lot of it has to do with the way their grandpa and their dad, and everyone else in their family, has done things.”

I asked Candy, well, what would you tell those producers?

“Get everyone to shift to complete no-till. Try to keep as much cover on the ground as possible — to reduce the amount of evaporation off of those soils down there that have a tendency to absorb a lot of heat and then just give it off in the way of evaporation.”

“That’s a huge deal for us in Kansas, where it’s typical to be up in the 100s and 20- or 30-mile per hour winds,” says producer Ryan Speer. “Evaporation loss is very, very high. So, anything we can do to mitigate that heat stress always benefits in yield.”

Playa Country, a weekly show about the wildlife, people and landscapes of the western Great Plains. Made possible by the Playa Lakes and Rainwater Basin Joint Ventures, and the Natural Resources Conservation Service.

Original broadcast: September 2014

Posted: July 24, 2015
Topics: Landowner Stories, Soil Health